Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Gas flow in near surface comet like porous structures: application to 67P/Churyumov-Gerasimenko


Hartogh,  Paul
Department Planets and Comets, Max Planck Institute for Solar System Research, Max Planck Society;

External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Christou, C., Dadzie, S. K., Thomas, N., Marschall, R., Hartogh, P., Jorda, L., et al. (2018). Gas flow in near surface comet like porous structures: application to 67P/Churyumov-Gerasimenko. Planetary and Space Science, 161, 57-67. doi:10.1016/j.pss.2018.06.009.

Cite as: https://hdl.handle.net/21.11116/0000-0001-E704-6
We performed an investigation of a comet like porous surface to study how sub-surface sublimation with subsequent flow through the porous medium can lead to higher gas temperatures at the surface. A higher gas temperature of the emitted gas at the surface layer, compared to the sublimation temperature, will lead to higher gas speeds as the gas expands into the vacuum thus altering the flow properties on larger scales (kilometres away from the surface). Unlike previous models that have used modelled artificial structures, we used Earth rock samples with a porosity in the range 24–92% obtained from X-ray micro computed tomography (micro-CT) scans with resolution of some μm. Micro-CT scanning technology provides 3D images of the pore samples. The direct simulation Monte Carlo (DSMC) method for the rarefied gas dynamics is directly applied on the digital rock samples in an unstructured mesh to determine the gas densities, temperatures and speeds within the porous medium and a few centimetres above the surface. The thicknesses of the rock samples were comparable to the diurnal thermal skin depth (5 cm). H2O was assumed to be the outgassing species. We correlated the coma temperatures and other properties of the flow with the rock porosities. The results are discussed as an input to analysis of data from the Microwave Instrument on Rosetta Orbiter (MIRO) on the 67P/Churyumov- Gerasimenko.